M. Tsuchiizu et al., Crossover from quarter-filling to half-filling in a one-dimensional electron system with a dimerized and quarter-filled band, J PHYS JPN, 70(6), 2001, pp. 1460-1463
The interplay between quarter-filled and half-tilled umklapp scattering has
been examined by applying the renormalization group method to a one-dimens
ional quarter-filled electron system with dimerization, on-site (U) and nea
rest-neighbor (V) repulsive interactions. The phase diagram on the U-V plan
e is obtained at absolute zero temperature where tile Mott, insulator (the
charge ordered insulator) is found for smaller (larger) V. By choosing the
moderate parameter in the region of Mott insulator, it is shown that tile r
esistivity exhibits a crossover from behavior of quarter-filling to that of
half-filling with decreasing temperature.